Go是更喜欢从远程存储库中获取还是更喜欢使用本地文件？

Question

Let's assume that my entire repository is at both github.com/my_repo and local file system. A source file imports "github.com/my_repo/pkg". When I run go run, does go fetch the remote file and import it, or does it prefer local files?

What if there is a generic remote repository (not github/launchpad/etc), will go prefer to fetch remote repository or prefer to use local files?

Answer 1

As per http://golang.org/doc/code.html#remote

If the specified package is not present in a workspace, go get will place it inside the first workspace specified by GOPATH. (If the package does already exist, go get skips the remote fetch and behaves the same as go install.)

Or, in other words:

1. Go will check for the package locally in your $GOPATH
2. If it doesn't exist, Go will call go get and fetch it.

This is worth noting if you are expecting a specific version of a repo: go will grab the latest for the version of Go installed. If the repo doesn't have specific tags, it will grab the head from the master branch. It's generally a good idea to note the version of the repo you need somewhere in your version control/documentation to ensure you don't get a later (and potentially breaking) repo.